Reconstituted CP29: multicomponent fluorescence decay from an optically homogeneous sample

Belgio, Erica; Tumino, Giorgio; Santabarbara, Stefano; Zucchelli, Giuseppe; Jennings, Robert C.

doi:10.1007/s11120-011-9696-3

Cited by 5 publications

(3 citation statements)

References 39 publications

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“…1). A similar increase in fluorescence lifetime in detergent-solubilized antennae was shown for antenna complexes from higher plants or diatoms [26,30]; this was rationalized by antennae aggregation in vivo that is minimal in the detergent-solubilized system [26] or by antennae perturbations as a result of a detergent-aqueous environment [33,34]. Quenching of the antenna fractions was induced in vitro using a method described previously [35][36][37] (Fig.…”

Section: Npq In the Isolated Antenna Complexes Is Inhibited By Violaxsupporting

confidence: 60%

Violaxanthin inhibits nonphotochemical quenching in light‐harvesting antenna of Chromera velia

et al. 2016

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Edited by Richard CogdellNon-photochemical quenching (NPQ) is a photoprotective mechanism in light-harvesting antennae. NPQ is triggered by chloroplast thylakoid lumen acidification and is accompanied by violaxanthin de-epoxidation to zeaxanthin, which further stimulates NPQ. In the present study, we show that violaxanthin can act in the opposite direction to zeaxanthin because an increase in the concentration of violaxanthin reduced NPQ in the light-harvesting antennae of Chromera velia. The correlation overlapped with a similar relationship between violaxanthin and NPQ as observed in isolated higher plant light-harvesting complex II. The data suggest that violaxanthin in C. velia can act as an inhibitor of NPQ, indicating that violaxanthin has to be removed from the vicinity of the protein to reach maximal NPQ.

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Section: Npq In the Isolated Antenna Complexes Is Inhibited By Violaxsupporting

confidence: 60%

Violaxanthin inhibits nonphotochemical quenching in light‐harvesting antenna of Chromera velia

et al. 2016

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“…Shown in Fig. 11 comparison of the calculated and measured absorption spectra 96 at room temperature. The absorption spectrum calculated at low temperature (77 K) is shown in Fig.…”

Section: Absorption Spectramentioning

confidence: 99%

Time-dependent atomistic simulations of the CP29 light-harvesting complex

Maity

Sarngadharan

Daskalakis

et al. 2021

The Journal of Chemical Physics

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Light harvesting as the first step in photosynthesis is of prime importance for life on earth. For a theoretical description of photochemical processes during light harvesting, spectral densities are key quantities. They serve as input functions for modeling the excitation energy transfer dynamics and spectroscopic properties. Herein, a recently developed procedure is applied to determine the spectral densities of the pigments in the minor antenna complex CP29 of photosystem II, which has recently gained attention because of its active role in non-photochemical quenching processes in higher plants. To this end, the density functional-based tight binding (DFTB) method has been employed to enable simulation of the ground state dynamics in a quantum-mechanics/molecular mechanics (QM/MM) scheme for each chlorophyll pigment. Subsequently, the time-dependent extension of the long-range corrected DFTB approach has been used to obtain the excitation energy fluctuations along the ground-state trajectories also in a QM/MM setting. From these results, the spectral densities have been determined and compared for different force fields and to spectral densities from other light-harvesting complexes. In addition, time-dependent and timeindependent excitonic Hamiltonians of the system have been constructed and applied to the determination of absorption spectra as well as exciton dynamics.

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“…Our findings suggest that the proposed extent to which closed RCIIs modulate the antenna chlorophyll lifetime should be reevaluated to account for the quenching effects of the proteolipidic membrane environment on the state of LHCII. In fact, it was previously shown that the LHCII fluorescence lifetime in liposomes at high protein/lipid ratios was not 4 ns, as for isolated trimers, but 2 ns (41), and an increasing number of studies are pointing to the effect of detergents on protein conformations, leading to different quenching states (42,43). It is therefore possible to consider that the 4 ns lifetime is an artificial condition that is induced by the detergent-aqueous environment and does not occur in vivo.…”

Section: The Chlorophyll Fluorescence Lifetime Of Lhcii-enriched Membranes Is Similar To That Of the Control In Both Light-harvesting Andmentioning

confidence: 99%

Higher Plant Photosystem II Light-Harvesting Antenna, Not the Reaction Center, Determines the Excited-State Lifetime—Both the Maximum and the Nonphotochemically Quenched

Belgio

Johnson

Jurić

et al. 2012

Biophysical Journal

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128

147

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The maximum chlorophyll fluorescence lifetime in isolated photosystem II (PSII) light-harvesting complex (LHCII) antenna is 4 ns; however, it is quenched to 2 ns in intact thylakoid membranes when PSII reaction centers (RCIIs) are closed (Fm). It has been proposed that the closed state of RCIIs is responsible for the quenching. We investigated this proposal using a new, to our knowledge, model system in which the concentration of RCIIs was highly reduced within the thylakoid membrane. The system was developed in Arabidopsis thaliana plants under long-term treatment with lincomycin, a chloroplast protein synthesis inhibitor. The treatment led to 1), a decreased concentration of RCIIs to 10% of the control level and, interestingly, an increased antenna component; 2), an average reduction in the yield of photochemistry to 0.2; and 3), an increased nonphotochemical chlorophyll fluorescence quenching (NPQ). Despite these changes, the average fluorescence lifetimes measured in Fm and Fm' (with NPQ) states were nearly identical to those obtained from the control. A 77 K fluorescence spectrum analysis of treated PSII membranes showed the typical features of preaggregation of LHCII, indicating that the state of LHCII antenna in the dark-adapted photosynthetic membrane is sufficient to determine the 2 ns Fm lifetime. Therefore, we conclude that the closed RCs do not cause quenching of excitation in the PSII antenna, and play no role in the formation of NPQ.

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Reconstituted CP29: multicomponent fluorescence decay from an optically homogeneous sample

Cited by 5 publications

References 39 publications

Violaxanthin inhibits nonphotochemical quenching in light‐harvesting antenna of Chromera velia

Violaxanthin inhibits nonphotochemical quenching in light‐harvesting antenna of Chromera velia

Time-dependent atomistic simulations of the CP29 light-harvesting complex

Higher Plant Photosystem II Light-Harvesting Antenna, Not the Reaction Center, Determines the Excited-State Lifetime—Both the Maximum and the Nonphotochemically Quenched

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